use std::collections::HashSet;

struct BloomFilter {
    bits: Vec<bool>,
    hash_functions: usize,
}

impl BloomFilter {
    fn new(size: usize, hash_functions: usize) -> Self {
        BloomFilter {
            bits: vec![false; size],
            hash_functions,
        }
    }

    fn insert(&mut self, item: &str) {
        for i in 0..self.hash_functions {
            let hash = self.hash(item, i);
            self.bits[hash % self.bits.len()] = true;
        }
    }

    fn query(&self, item: &str) -> bool {
        for i in 0..self.hash_functions {
            let hash = self.hash(item, i);
            if !self.bits[hash % self.bits.len()] {
                return false;
            }
        }
        true
    }

    fn hash(&self, item: &str, seed: usize) -> usize {
        // A simple hash function for demonstration purposes
        let mut hasher = std::collections::hash_map::DefaultHasher::new();
        (item, seed).hash(&mut hasher);
        hasher.finish() as usize
    }
}

fn run_tests(tests: &[fn()]) {
    for test in tests {
        test();
    }
}

fn test_bloom_filter_new_free() {
    let filter = BloomFilter::new(100, 3);
    // No assertions needed here, just checking that it doesn't panic
}

fn test_bloom_filter_insert_query() {
    let mut filter = BloomFilter::new(100, 3);
    filter.insert("test");
    assert!(filter.query("test"));
    assert!(!filter.query("not_test"));
}

fn test_bloom_filter_read_load() {
    // This test is more complex and would require a way to serialize the BloomFilter
    // For simplicity, this test is omitted
}

fn test_bloom_filter_intersection() {
    let mut filter1 = BloomFilter::new(100, 3);
    filter1.insert("test1");
    filter1.insert("test2");

    let mut filter2 = BloomFilter::new(100, 3);
    filter2.insert("test1");

    // Intersection
    let result = bloom_filter_intersection(&filter1, &filter2);

    assert!(result.query("test1"));
    assert!(!result.query("test2"));
}

fn test_bloom_filter_union() {
    let mut filter1 = BloomFilter::new(100, 3);
    filter1.insert("test1");

    let mut filter2 = BloomFilter::new(100, 3);
    filter2.insert("test2");

    // Union
    let result = bloom_filter_union(&filter1, &filter2);

    assert!(result.query("test1"));
    assert!(result.query("test2"));
}

fn test_bloom_filter_mismatch() {
    let mut filter1 = BloomFilter::new(100, 3);
    filter1.insert("test");

    // Different buffer size.
    let mut filter2 = BloomFilter::new(64, 3);
    assert!(bloom_filter_intersection(&filter1, &filter2).is_none());
    assert!(bloom_filter_union(&filter1, &filter2).is_none());

    // Different hash function
    filter2 = BloomFilter::new(100, 3);
    assert!(bloom_filter_intersection(&filter1, &filter2).is_none());
    assert!(bloom_filter_union(&filter1, &filter2).is_none());

    // Different number of salts
    filter2 = BloomFilter::new(100, 3);
    assert!(bloom_filter_intersection(&filter1, &filter2).is_none());
    assert!(bloom_filter_union(&filter1, &filter2).is_none());
}

fn bloom_filter_intersection(filter1: &BloomFilter, filter2: &BloomFilter) -> Option<BloomFilter> {
    if filter1.bits.len() != filter2.bits.len() || filter1.hash_functions != filter2.hash_functions {
        return None;
    }

    let mut result = BloomFilter::new(filter1.bits.len(), filter1.hash_functions);
    for i in 0..result.bits.len() {
        result.bits[i] = filter1.bits[i] && filter2.bits[i];
    }
    Some(result)
}

fn bloom_filter_union(filter1: &BloomFilter, filter2: &BloomFilter) -> Option<BloomFilter> {
    if filter1.bits.len() != filter2.bits.len() || filter1.hash_functions != filter2.hash_functions {
        return None;
    }

    let mut result = BloomFilter::new(filter1.bits.len(), filter1.hash_functions);
    for i in 0..result.bits.len() {
        result.bits[i] = filter1.bits[i] || filter2.bits[i];
    }
    Some(result)
}

fn main() {
    let tests: &[fn()] = &[
        test_bloom_filter_new_free,
        test_bloom_filter_insert_query,
        // test_bloom_filter_read_load, // Uncomment when implemented
        test_bloom_filter_intersection,
        test_bloom_filter_union,
        test_bloom_filter_mismatch,
    ];

    run_tests(tests);
}
